For most of us, autumn's falling temperatures and shrinking days indicate the end of 2012's backyard growing season and a break from all that digging, weeding, planting and harvesting.

But before you call it quits for the winter, you might consider undertaking one final chore. Consider it prep work for spring: soil testing.

Should I Test?

It's a rather disconcerting fact that, although you may be extremely picky about what's mixed into your garden's soil and sprayed on your plants, previous owners of the land likely weren't so scrupulous. And even if they were as careful as you, there's little anyone can do to keep contaminants from old-school construction materials and industrial pollution from permeating the ground.

This means, in spite of your best efforts, the dirt in your yard may very well harbor elevated concentrations of substances you'd probably prefer not to ingest -- substances like lead, arsenic, cadmium and dry cleaning chemicals.

So if you live in an urban area, are neighbors with a factory or refinery, or just don't know the history of your property, you may want to consider having your soil's chemistry analyzed. Conveniently, there are labs all across the country that do this sort of thing (a web search is a quick way to find one), and October and November are the best months to take samples!

Remediation

Thankfully, if your soil tests positive for something unsavory, or if testing turns out to be prohibitively expensive, there are steps you can take to make your backyard operation cleaner and safer.

The easiest countermeasure is simply to wash and peel your veggies really well. Much harmful exposure comes by way of contact with the dust clinging to the outside of produce. Eliminate the dust, and you'll eliminate a lot of the nasty stuff.

Something else you can do is make sure your soil's pH is 6.5 or higher by composting. Not only will this keep plants from taking up dangerous chemicals, it'll make your plants grow better too.

Finally, if you're feeling especially ambitious, you might pursue a more architectural stratagem. Growing food in raised garden beds allows you to control exactly what kind of soil your veggies are growing in. Just make sure you're not using treated wood.

Read More

• PDF: Urban Gardens And Soil Contaminants (University of Minnesota)
• Reducing Exposure To Soil Contaminants From Urban Gardening (The National Institute of Environmental Health Sciences)
• Swainway Urban Farm: Growing Carrots, Prepping Raised Beds (Earth Eats)
• High Lead Found In City-Sourced Eggs (New York Times)